data_global _chemical_name_mineral 'Diopside' loop_ _publ_author_name 'Thompson R M' 'Downs R T' _journal_name_full 'American Mineralogist' _journal_volume 93 _journal_year 2008 _journal_page_first 177 _journal_page_last 186 _publ_section_title ; The crystal structure of diopside at pressure to 10 GPa Sample: P = 8.01 GPa ; _database_code_amcsd 0004501 _chemical_compound_source 'DeKalb, New York' _chemical_formula_sum 'Mg Ca Si2 O6' _cell_length_a 9.5557 _cell_length_b 8.6951 _cell_length_c 5.1474 _cell_angle_alpha 90 _cell_angle_beta 105.148 _cell_angle_gamma 90 _cell_volume 412.826 _exptl_crystal_density_diffrn 3.484 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Mg 0.00000 0.90998 0.25000 0.00519 Ca 0.00000 0.30528 0.25000 0.00925 Si 0.28595 0.09523 0.22701 0.00646 O1 0.11494 0.08890 0.14173 0.00874 O2 0.35903 0.25554 0.32144 0.00975 O3 0.35425 0.02211 0.98887 0.00823